Adjustable flow control valve for fuel gas



Jan. 12, 1965 A. FINELT 3,165,117

ADJUSTABLE mow CONTROL VALVE FOR FUEL GAS Filed June 7, 1961 FIG. 2

United States Patent '0 3,165,117 ADJUSTABLE FLGW CONTROL VALVE FGR FUEL GAS Aron Finelt, 13017 236th St., Laurelton, NX. Filed June 7, 1961, Ser. No. 115,396

- 1 Claim. (Cl. 137-614.17)

The object of the invention is to provide a fuel gas control for ovens and heat treating furnaces, primarily for employment in the manufacture of jewelry, and which has more general use, as for example in heat treating small metal parts. Thus as a step in=the cast-metal production of jewelry, it is customary procedure to form a wax pattern of the item or items to be reproduced, to invest the pattern with a ceramic mixture, which is then set, and to burn out the wax from the mold cavity thus formed, thus providing a mold for repeated casting of the jewelry items, or other small objects to be reproduced in cast metal.

In the use of furnaces for wax burnout or for heat treatment of relatively small metal cast objects, the heat is progressively applied, and in the case of wax burnout, the temperature is brought to a maximum of about 1300" F. to completely eliminate the carbon residue. Thus in current practice, the initial temperature degree is brought to 450500 F. for a period of time, then raised to medium temperature which may be as high as 950 R, which is maintained for a period of time, whereupon the high temperature, generally 1300 F.1350 F. is maintained until the burnout is completed.

By means of the present invention, predetermined and successive required temperatures in a gas-fired furnace may be obtained by step by step rotation of a specially formed assembly of control elements and valve, and as to the control element by its rotation, as now to be described.

The invention will be described with reference to the accompanying drawings, in which:

FIG. 1 is a perspective view of a suitable furnace, with the control valve applied thereto in horizontal position;

FIG. 2 is a view similar to FIG. 1 showing the valve in vertical position;

FIG. 3 is a longitudinal section through the control valve;

FIG. 4 is a vertical section on the line 44, FIG. 3.

The invention is particularly applicable to the lost wax process.

Referring to the drawings, it will be seen, with reference to FIGS. 3 and 4, that the valve applied to the furnace 1 consists of a casing 2, formed with a central primary chamber, which receives the rotational control element. This element, hereinafter termed the valve rotor, consists of an innermost member 3 of the valve rotor having a rearwardly extending stub shaft 4 which is passed through a rear opening in block 2. Rotational member 3 of the valve rotor is cylindrical and closely fits the inner wall of the block chamber, and at its end stub shaft 4 carries a headed screw-stud 5 threaded into the stub shaft and engaged by a coil spring 6, preferably via an intermediate washer 7. By such means, rotational member 3 is maintained in close contact with the tapered annular inner wall of the chamber formed in casing 2. At the front end of easing 2 a head 8 is suitably secured to valve rotor 3 by means of screws (one being shown in FIG. 3) 9 or by any other suitable means. Head 8 is adapted for manual rotation of rotor 3 and preferably formed with an annular projection 8x to receive an apertured cap 10. Normally shielded by cap 10 are a plurality of adjustable valve-opening control members now to be described.

The inlet for the valve consists of a hollow stem 11 adapted to receive a conduit leading to a source of gas supply, casing 2 having an aperture at 12 in alignment therewith. The primary outlet for casing 2 is shown in FIG. 3 at 14 and it communicates with an apertured stem 15 for connection with a conduit 16, FIG. 1, leading to the burner (not shown) in the furnace 1.

In the present embodiment, inlet 12 may be brought into communication with any one of five apertures leading to the interior of valve rotor, and which in FIG. 4 are shown at 16, 17, 18, 19 and 20. Also in valve rotor, five gas flow apertures are provided for communication with outlet passage 14. As shown in FIG. 3, each of said apertures is formed in valve rotor with a longitudinal lead communicating with a lateral lead. These outward gas flow passages in valve rotor are indicated by dotted lines in FIG. 4 at 21, 22, 23, 24 and 25.

The adjustable valve control members are carried by member 8. Each consists of a threaded stem passed through a threaded opening in member 8 and projected into a chamber in cap 10. Removal of the cap will, as to each threaded stem, expose the end of the latter for rotation after release of a lock nut such as indicated at 26, FIG. 3, and the end of the stern may be slotted to receive a small screw driver element for rotation of the stem. Each stem is in line with the longitudinal lead of one of the openings 21 to 25 inclusive, so as to control the amount of gas passing into and out of the appropriate passageway. In the present embodiment, there being five gas outflow passageways, controlled by five valve stems, five separate heats are provided for the furnace 1. The inlets 16 to 20 inclusive are merely to enable flow of gas into control member 3 whenever rotation of the control brings an appropriate gas outflow passage 21 to 25 inclusive into communication with the outflow passage 14 in casing 2.

Each valve stem 30, 31, 32, 33 and 34 is alined with its appropriate gas outflow opening or passageway in control member 3, and each stem has a head with a rounded end surface. In the use of the device, each valve stem will be adjusted relatively to the gas opening or passageway which it controls, so that a predetermined volume of gas will be passed from the passageway to the burner in accordance with the temperature required for that specific control. Therefore in repeated operations of the furnace for progressive changes in temperature, the preset valve stems will be retained in position, and the cap 10 and control member 8 will be rotated a prescribed step or steps for each required temperature change. The control member 8 will be marked with indicia spaced in accordance with the valve stems and a pointing finger 35, FIG. 3, will indicate the proper register of control memher 8 for each successive degree of heat. Thus one of the valve stems will be set for an initial low temperature, say 450 F.; the next valve stem for, say 950 F.; and the remaining valve stems pre-adjusted for higher temperatures.

One of the control valve stems may be adjusted for a metal casting temperature of say 1,0001,100 F. for certain jewelry casting metals other than platinum, and one of the valve stems may be adjusted for casting platinum, as for example 1,700" P.

Having described my invention, what I claim and desire to secure by Letters Patent is as follows:

An adjustable flow control valve for fuel gas comprising a unitary casing formed with a central chamber having a front opening which is relatively large and a rear bearing-opening of relatively small diameter, a valve rotor in said chamber, said rotor having a rear sub-shaft rotationally fitting the rear bearing opening of the casing and said rotor being provided with an open end chamber at its rear, said chamber being surrounded by an annular wall of the rotor, a plurality of spaced gas inlet openings in said annular wall, a gas inlet duct in the casing in line with said spaced inlet openings of the rotor annular Wall, a plurality of spaced outlet gas passages in the rotor and communicating with its chamber, each of said outlet gas passages having a lead extending longitudinally of the rotor and having a lateral lead, an outlet passage in the casing and in line with the lateral leads of said last named outlet passages of the rotor, a rotor head abutting and closing the chamber of the rotor and removably secured thereto, said rotor head being exposed for manual rotation of the rotor, a plurality of valve stems threaded in said rotor head and projecting into the rotor chamber, each valve stem being in line with one of said outlet gas passages of the rotor and each valve stem having an end projected through the rotor head and adjustable forand any outlet gas passage of the rotor aligned with the casing outlet is in communication with an inlet passage of the rotor and with the casing inlet duct.

References Cited by the Examiner UNITED STATES PATENTS wardly and rearwardly, relatively to the rotor chamber 15 M. CARY NELSON m ry Examiner- 

